"Briton" is shivering after the failure of the Gulf Stream, in the bleak world presented in Blown Away. The Government has introduced rationing.
Flooding and storms are the dominant weather pattern. There are wars in the Mediterranean and a flu epidemic. The current switch-off has happened almost overnight, picking up the themes of Patrick Cave's highly acclaimed thriller Sharp North, to which this is a sequel. His new futuristic nightmare begins in 2023 when 14-year-old Dominic has been left in his abandoned public school, to be rounded up for some very unpleasant military training aimed at selecting the most promising stock from which to clone new Britons.
Take the temperatures plunging downwards for another few 100 years to pick up the story of Adeline, practising karate in the warmth of the Pyrenees.
Over in freezing Briton, Jan Barbieri rules through fear and violence, creating a population hooked on a TV combat show called Fit to Live in which weak contestants die. Adeline is a strange, fearless creature: a clone with a flawed heart, who embraces cold like a drug and has a mission to challenge Barbieri.
Cave keeps the two stories running parallel in a mesmerising, demanding read. However, Blown Away is a sombre warning I would be wary of giving it to someone too inclined to brood about the future. Cave warns that clones of the present generation cannot save us from something which may happen "as little as 15 years from now", but only people who love and think differently.
Chris Wooding's Storm Thief is a gripping read from the opening chapter, in which he realises the bleakness of a bare seascape and the plight of a lone seabird lost on its way to the breeding grounds. The bird crashes into the island of Oronokos, a teeming mid-ocean city with warrens of subterranean streets resembling a North African souk. The ruling Protectorate keeps the populace in ignorance of life beyond the towering cliffs of their seabound fastness, and the bird provides a rare clue that there is a life beyond.
At the heart of Oronokos' suffering lies the Chaos Engine, and the probability storms which can move streets around overnight and turn children into statues of ice. Rail, a young dreadlocked thief, and his girlfriend Moa scrape a dangerous living by stealing to order, but incur their gang lord's wrath when they hide a stolen artefact which enables them to walk through walls.
Wooding's powerful blend of thriller, science fiction and fantasy is about love, hope and uncertainty. Rail and Moa's love is based on a profound need to look after one another, but Rail sees his life as irrevocably linked to Oronokos, whereas Moa believes there is life beyond.
After the subterranean horrors of Storm Thief, David Cunningham's debut novel Cloud world is a breath of fresh air. Marcus, the prince of Heliopolis, has lived his life in the sunlight. His father's feudal kingdom is a citadel built above the cloud layer. No one knows what lies below, but when the king's sabotaged aero-cruiser sinks beneath the cumulus, Marcus joins the rescue party and finds himself among warring communities who teach him the need for equality.
Cunningham has a clear eye for cloudscapes and the murkier landscapes below, but his story proceeds in a prose style, which will show young readers how to write proper sentences, but lacks crackle. Famished explorers may eat with "complete disregard for dining decorum", but - burp, pardon me - scruffy eating demands scruffy writing. Cloud world is not a story which leaves much to dwell on, but readers aged 10 to 12 who enjoy battle scenes will be well satisfied.
If you could reverse time, would the sand in egg-timers flow upwards? Apparently not, so you could still measure the precious two minutes available to save yourself from destruction. Eoin McNamee's The Navigator is based on the intriguing idea that outside ordinary time lurks a band of nasties who want to send the world into reverse and eliminate all life.
Young Owen finds himself treated to the possibility of a few centuries off school when he wanders from his secret den to find his suburban streets have become ancient scrubland, but it soon becomes his mission to reach the Great Machine in the North to start time running in the right direction again. This is another battle-packed adventure, but it seems to miss opportunities offered by its central idea.
David Buckley is a part-time English teacher in Sheffield
By Patrick Cave
Simon and Schuster pound;12.99
By Chris Wooding
By David Cunningham
Faber pound;6.99 (paperback)
By Eoin McNamee